Drift theory of charged-particle motion in quasimonochromatic wave

The nonrelativistic motion of a charged particle in a quasimonochromatic wave is considered in the drift-theory approximation, in the case of a "strong" electric field. It is shown that, in contrast to the case of a "weak" electric field, the strong field may appear in the averaged first-approximation equations. The conservation laws are discussed. © 1979 Plenum Publishing Corporation.